This invention relates to improved methods and apparatus for manufacturing threaded nuts of a type utilizing a wiredrawn helical coil structure for forming a thread.
In my prior U.S. Pat. Nos. 3,272,250 and 3,283,350, and in certain other prior patents, I have disclosed a type of nut in which the thread proper is formed separately from and is contained within an outer case or body structure of the nut. More particularly, the thread is formed as an essentially helical resilient coil structure, desirably made from a wire drawn to a proper cross sectional configuration to present at its radially inner side a suitable thread profile for engaging a coacting screw. Preferably, at least a portion of the coil structure is rigidly bonded to the outer case to form an integrated assembly having adequate strength to properly withstand all of the forces which may be encountered in use. Such a nut may be given a self-locking action by deforming a portion of the coil structure to a condition in which it has an interference fit with the coacting screw, and must be forced by the screw to a changed condition upon threaded interengagement of the two parts.